/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package pcloud.server;

import java.io.IOException;
import java.net.InetAddress;
import java.net.SocketException;

import org.apache.ftpserver.command.AbstractCommand;
import org.apache.ftpserver.command.impl.LIST;
import org.apache.ftpserver.command.impl.listing.DirectoryLister;
import org.apache.ftpserver.command.impl.listing.LISTFileFormater;
import org.apache.ftpserver.command.impl.listing.ListArgument;
import org.apache.ftpserver.command.impl.listing.ListArgumentParser;
import org.apache.ftpserver.ftplet.DataConnection;
import org.apache.ftpserver.ftplet.DataConnectionFactory;
import org.apache.ftpserver.ftplet.DefaultFtpReply;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpFile;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.impl.FtpIoSession;
import org.apache.ftpserver.impl.FtpServerContext;
import org.apache.ftpserver.impl.IODataConnectionFactory;
import org.apache.ftpserver.impl.LocalizedFtpReply;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * <strong>Internal class, do not use directly.</strong>
 * 
 * <code>NOOP &lt;CRLF&gt;</code><br>
 * 
 * This command does not affect any parameters or previously entered commands.
 * It specifies no action other than that the server send an OK reply.
 * 
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public class TASK extends AbstractCommand
{
    private final Logger LOG = LoggerFactory.getLogger(LIST.class);

    private static final LISTFileFormater LIST_FILE_FORMATER = new LISTFileFormater();

    private DirectoryLister directoryLister = new DirectoryLister();


	/**
	 * Execute command
	 */
	public void execute(final FtpIoSession session,
			final FtpServerContext context, final FtpRequest request)
			throws IOException, FtpException
	{
		try {

			// reset state variables
			session.resetState();

			// parse argument
			ListArgument parsedArg = ListArgumentParser.parse(request
					.getArgument());

			// checl that the directory or file exists
			FtpFile file = session.getFileSystemView().getFile(
					parsedArg.getFile());

			if (!file.doesExist()) {
				LOG.debug("Listing on a non-existing file");
				session.write(LocalizedFtpReply.translate(session, request,
						context,
						FtpReply.REPLY_450_REQUESTED_FILE_ACTION_NOT_TAKEN,
						"LIST", null));
				return;
			}

			// 24-10-2007 - added check if PORT or PASV is issued, see
			// https://issues.apache.org/jira/browse/FTPSERVER-110
			DataConnectionFactory connFactory = session.getDataConnection();
			if (connFactory instanceof IODataConnectionFactory) {
				InetAddress address = ((IODataConnectionFactory) connFactory)
						.getInetAddress();
				if (address == null) {
					session.write(new DefaultFtpReply(
							FtpReply.REPLY_503_BAD_SEQUENCE_OF_COMMANDS,
							"PORT or PASV must be issued first"));
					return;
				}
			}

			// get data connection
			session.write(LocalizedFtpReply.translate(session, request,
					context, FtpReply.REPLY_150_FILE_STATUS_OKAY, "LIST", null));

			DataConnection dataConnection;
			try {
				dataConnection = session.getDataConnection().openConnection();
			} catch (Exception e) {
				LOG.debug("Exception getting the output data stream", e);
				session.write(LocalizedFtpReply.translate(session, request,
						context, FtpReply.REPLY_425_CANT_OPEN_DATA_CONNECTION,
						"LIST", null));
				return;
			}

			// transfer listing data
			boolean failure = false;

			try {
				dataConnection
						.transferToClient(session.getFtpletSession(),
								directoryLister.listFiles(parsedArg,
										session.getFileSystemView(),
										LIST_FILE_FORMATER));
			} catch (SocketException ex) {
				LOG.debug("Socket exception during list transfer", ex);
				failure = true;
				session.write(LocalizedFtpReply.translate(session, request,
						context,
						FtpReply.REPLY_426_CONNECTION_CLOSED_TRANSFER_ABORTED,
						"LIST", null));
			} catch (IOException ex) {
				LOG.debug("IOException during list transfer", ex);
				failure = true;
				session.write(LocalizedFtpReply
						.translate(
								session,
								request,
								context,
								FtpReply.REPLY_551_REQUESTED_ACTION_ABORTED_PAGE_TYPE_UNKNOWN,
								"LIST", null));
			} catch (IllegalArgumentException e) {
				LOG.debug("Illegal list syntax: " + request.getArgument(), e);
				// if listing syntax error - send message
				session.write(LocalizedFtpReply
						.translate(
								session,
								request,
								context,
								FtpReply.REPLY_501_SYNTAX_ERROR_IN_PARAMETERS_OR_ARGUMENTS,
								"LIST", null));
			}

			// if data transfer ok - send transfer complete message
			if (!failure) {
				session.write(LocalizedFtpReply.translate(session, request,
						context, FtpReply.REPLY_226_CLOSING_DATA_CONNECTION,
						"LIST", null));
			}
		} finally {
			session.getDataConnection().closeDataConnection();
		}
	}
}
